The departure of Yemen's battle-wounded president for treatment in Saudi Arabia set off wild street celebrations Sunday in the capital, where crowds danced, sang and slaughtered cows in hopes that this spelled a victorious end to a more than three-month campaign to push their leader from power.

Behind the festive atmosphere, many feared Ali Abdullah Saleh, a masterful political survivor who has held power for nearly 33 years, will yet return — or leave the country in ruins if he can't. Hanging in the balance was a country that even before the latest tumult was beset by deep poverty, malnutrition, tribal conflict and violence by an active al-Qaida franchise with international reach.

Saleh, who was taken overnight to a military hospital in the Saudi capital, Riyadh, underwent successful surgery on his chest to remove jagged pieces of wood that splintered from a mosque pulpit when his compound was hit by rockets on Friday, said medical officials and a Yemeni diplomat. They spoke on condition of anonymity because they did not have permission to release the information.